Complete cessation of antibiotic use for the treatment of clinical mastitis may lead to increased clinical mastitis incidence and increased expenses in the long term. Joshi and Shrestha (1995) reported that the incidence of bovine clinical mastitis in the Western Hills of Nepal was highest (17.6%) during 1st lactation, and decreased in successive lactations. The incidence of clinical mastitis was higher in younger animals and found more than 88.8% during the 1st month of lactation.
The prevalence of clinical mastitis was found to vary significantly (p<0.01) according to herd size, breed, stage of lactation and milk yield. The highest prevalence of subclinical mastitis has been observed in crossbred Jersey and Holstein cows producing 5-9 kg of milk per morning. A case-control study was conducted by Waage et al. 2000) evaluated risk factors for clinical mastitis in dairy heifers between days 1 and 14 of calving.
Separate analysis of a subset of case-control pairs identified teat edema, blood in the milk, and milk leakage at calving as risk factors for clinical mastitis caused by Staphylococcus aureus. 2000) describes the risk factors that influence the incidence of infection and the occurrence of clinical mastitis. Joshi and Shrestha (1995) reported that the incidence of bovine clinical mastitis in the western hills of Nepal was the highest (17.6%) during the 1st lactation, decreasing in successive lactations. The incidence of clinical mastitis was higher in younger animals and found more than 88.8% during the 1st month of lactation.
Clinical mastitis as reported by Barker (1998) in the first 150 days of lactation had a highly negative effect on length of service.
METERIALS AND METHODS
- Study Area
- Duration of Study
- Source of Population
- Sampling Methods
- Study Population
- Study Design
- Data collection
- Diagnostic Procedure
- Treatment regimens
- Data Analysis
The prevalence of clinical mastitis was determined across Sirajgonj Sadar Upazilla based on clinical examination, palpation, observation of milk secretion. A structured questionnaire was developed and selected farm owners or farmers were interviewed and the pre-tested questionnaire was filled. Diagnosis of clinical mastitis performed on the basis of clinical signs shown by the animals.
Treatment of clinical mastitis is difficult, due to drug tolerance and drug residues in milk. The mild cases were treated with intramammary antibiotics [Neomastipra (1 syringe/ affected quarter every 12 hours; each syringe contains benzylpenicillin 1000000 IU, dihydrostreptomycin 62.4mg, neomycin 36mg, polymyxin 3U, 25000mid and 25000mid hydroxy. ), Pharma and Pharma Ltd. , Bangladesh] for 3 days after milking. The moderate cases were treated with systemic antibiotics and anti-inflammatory drugs [Gentasone-5 (1ml/10kg body weight, intramuscular for 1st day with 12 hour interval and then with 24 hour interval; each ml contains 50mg Gentamycin), Chemist ltd., Bangladesh and Kop-Vet (intramuscular 3mg Ketoprofen/kg body weight daily; each 100ml solution contains ketoprofen 10mg), Square ltd., Bangladesh] for 3 days.
Clinical examination of cows was performed 10 days after the end of treatment to determine outcome. The incidence of clinical mastitis was the dependent variable while source of patient, herd size, age, breed, general physical condition, lactation number, lactation stage and quarter involvement were independent variables considered at the cow level.
CHAPTER-lV
RESULTS AND DISCUSSIONS
FREQUENCY AND DISTRIBUTION OF MASTITIS
- Overall prevalence and breed-based distribution of mastitis
- Age-based distribution of mastitis
- Lactation number-based prevalence of mastitis
- Stage of lactation-based prevalence of mastitis
- Quarter prevalence rate of mastitis in cows
The increase in the prevalence rate with age may be due to the gradual suppression of the body's immune system. The prevalence is more widespread in higher age groups, the higher the rate of breastfeeding, the higher the chance of the disease (Chakrabati, 1997). The present findings are supported by Rasool et al. 1985) who reported that the incidence of mastitis increases with age.
It was found that the occurrence of mastitis increased as the number of lactations in cows increased. The prevalence was highest during the first month of lactation (12.99%) and gradually decreased in the second and third months of lactation (8.57% and 5.94%). The higher prevalence rate during the first month of lactation is an indication of an infection, probably prior to freshening.
It usually depends on the defense mechanism of udder, including lysozyme, lactoferrin, immunoglobulins and leukocytes (Rodostits et al., 2000). Risk factors associated with the occurrence of mastitis including teat soreness, pendulous udders, udder asymmetry, peri-partum udder oedema, average teat diameter in herd and concurrent disease of animals (Hogan et al., 1996).
DETERMINANTS/RISK FACTORS OF MATITIS IN COWS
- General physical condition of cows
- Herd size of cows
- Frequency of dung removal
- Floor drainage quality
- Condition of Floor
- Effect of reproductive diseases
The present findings revealed a highly significant association between general physical condition and the prevalence of mastitis in cows. It has been suggested that high milk production could predispose animals to udder infections. 1997) also concluded that poor health management may be responsible for the higher prevalence of mastitis in small herds. As the herd size increases, the prevalence of clinical mastitis is lower than that of individual households (Rehman et al., 1997).
It may be due to poor hygiene practices and disease control program (Parai et al., 1992). Table-8: Distribution and association of clinical mastitis with frequency of manure removal in a dairy farm. In the present study, a significant relationship between the frequency of manure removal and the prevalence of mastitis was revealed in cows.
When cleaning barns was practiced more than twice a day, 6.11% incidence of mastitis was observed. Only a marginal decrease in mastitis with increasing frequency of manure removal can be explained by the fact that mastitis in Bangladesh and other developing countries lacking the application of standard mastitis control is predominantly infectious in nature (Allore, 1993). Table-9: Prevalence and association of clinical mastitis with floor drainage quality of dairy farm. of Affected cows Mastitis Occurrence.
Only slightly higher prevalence of mastitis in cows, 10.78% were managed with poor quality soil drainage than in those managed with proper drainage 2.44%. can be explained by the same reasoning. 1990) reported that herds with a liquid system were at greater risk of mastitis prevalence than herds with a solid system. The prevalence of mastitis was 6.98% with concrete or brick floors and 9.09% in farms with floors. This can be explained by the fact that farms with soil would dry out faster than with brick floors (Hogan et al have shown lack of water as one of the possible risk factors for the prevalence of mastitis.
Poor quality management of housing and bedding increases infection rate due to environmental pathogen (Rodistitis et al., 2000). Table-11: Prevalence and association of clinical mastitis with the presence of reproductive diseases of dairy cows. Cows without a history of periparturient disease had an incidence of 3.29% mastitis; in contrast, 32.46% of cows with a history of periparturient disease had mastitis.
Once a cow becomes infected or ill during the periparturient period, it becomes more susceptible to udder infection due to reduced immunity (Nickerson, 1994; Peeler et al., 1994). Additionally, cows with infected uterine discharge and retained placenta walk the udder and teats to become infected (Peeler et al., 1994).
EFFICIENCY OF TREATMENT REGIMENS
The ultimate treatment for clinical mastitis will result in rapid clinical recovery, minimize pain and suffering, avoid unnecessary medication use or excessive labor, limit adverse effects on milk production, and be economical and safe. The study was conducted to find out the prevalence, risk factors and effectiveness of different treatment regimens on clinical mastitis in the cows of Sirajgonj sadar upazila, Bangladesh. Although the overall prevalence of clinical mastitis in cows was relatively lower in the study area, but the prevalence was higher in crossbred cows than in native cows.
There was a significant relationship between the prevalence of clinical mastitis and associated risk factors such as general physical condition, herd size, frequency of litter removal, floor drainage quality and floor condition. This study also focused on antibiotic treatment through different routes of clinical mastitis during lactation. Appropriate treatment regimens should be followed by determining the severity of mastitis in order to reduce the economic loss and reduce the prevalence of the disease various epidemiological factors that interact in the occurrence of mastitis.
DeMello, 1974. Incidence of bovine mastitis in the dairy area of the southern Agrestezone of Pernambuco, Dept de Microbiol. A study on the prevalence of clinical mastitis in cattle and buffaloes under different management systems in the western hills of Nepal. Influence of host-level factors on the prevalence and economics of subclinical mastitis in dairy cows in Bangladesh.
Microbiological Procedures for the Diagnosis of Bovine Udder Infections, National Mastitis Council Inc. Control of mastitis in dairy herd hygiene and management. A note on diagnosis of subclinical bovine mastitis and in vitro drug susceptibility testing of bacterial isolates. Studies on subclinical mastitis in crossbreeds under hot humid conditions in West Bengal.
Epidemiological criteria of the association between the incidence of mastitis and some predisposing factors.
